A working device as a hedge trimmer in which a blade linearly moves forward and backward, has a power transmission mechanism that converts the torque transmitted from a driving source to the reciprocating linear motion of a blade. A general power transmission mechanism used in a hedge trimmer has a structure where a gear rotating by the power of a driving source has an eccentric cam, and this eccentric cam is coupled with a blade via a crank member to convert the torque of the gear to the reciprocating linear motion of the blade.
With this power transmission mechanism, an eccentric cam and a crank member slide continuously in contact with one another, and therefore, it is necessary to consistently apply lubricant such as grease to the sliding contact surface. Here, in a working device disclosed in Patent Literature 1, a concave part is formed in a sliding contact surface between an eccentric cam and a crank member, and lubricant supplied to the concave part using pressure fluctuation caused by variations in the capacity of a gear storage chamber.